Feuling Lifters - Race Series (4050 / 4017) — Harley-Davidson Softail Heritage Classic, Road King, Softail Fat Boy (1999-2025)

Feuling Race Series hydraulic lifters engineered for high-lift cams and aggressive valve spring pressures on street and strip V-twin engines. Steel-bodied construction with a slower bleed-down rate maintains oil delivery to the top end and reduces valve float at elevated RPM.

Features

• Steel body construction
• Slower bleed-down rate for high-lift cams
• Supports valve spring pressures above 185 lbs. seat pressure
• Increases RPM capability and valve-train stability
• Compatible with Feuling HP+ or Race Series oil pumps
• Spin-Tron dyno-developed and track-proven
• Made in the U.S.A.

Specifications

• Brand: Feuling
• Manufacturer Part #: 4017
• Length: 5 in
• Width: 6.2 in
• Height: 3.45 in
• Weight: 1.3 lbs

Fitment

Fits V-twin motorcycles. Recommended for engines running valve spring seat pressures higher than 185 lbs.

Frequently Asked Questions

What valve spring pressure do these lifters support?

Race Series lifters are recommended for engines running higher than 185 lbs. valve spring seat pressure. Lower pressures will work but may not deliver the performance benefit.

Do I need a high-volume oil pump with these lifters?

Feuling recommends a high-volume oil pump to achieve quieter operation and optimal performance. Race Series lifters are compatible with both Feuling HP+ and Race Series oil pumps.

Can I use these on a street engine?

Yes — these lifters are designed and track-proven for both street and strip engines with aggressive cam profiles.

What's the difference between Race Series and standard lifters?

Race Series lifters have a slower bleed-down rate and support higher valve spring pressures, making them better for large-lift cams and elevated RPM applications.